Why was Broadcom BCM2836 chosen as the CPU for RPi?

[helpme]

Given that there are plenty of processors out there, why was Broadcom BCM2836 chosen as the CPU for RPi? What were the advantages of BCM2836 versus the other CPUs out there? For example, why not choose Intel CPUs which are quite a safe choice given the Intel brand? (I'm not related to Intel)

[W. H. Heydt]

Intel processors are (a) expensive compared to ARM chips, and (b) power hogs compared to ARM chips.

One factor behind the choice of Broadcom is that Eben Upton and some of the others who did the initial work on the Pi work or worked for...Broadcom. Broadcom was generous enough to allow the RPF to buy modest lots of BCM2835 chips at a price normally reserved for much higher volumes. Of course, after the first few months, the volumes of chip purchases were at a level that the price was "normal". By using the BCM2835, those doing the early software work got a leg up be being already familiar with various parts of the chip architecture. So...a win-win. Broadcom gets really good PR (hasn't the Pi made you think kindly about Broadcom?) and the RPF got a good deal to help get the project successfully off the ground.

[helpme]

Intel processors are (a) expensive compared to ARM chips, and (b) power hogs compared to ARM chips.

One factor behind the choice of Broadcom is that Eben Upton and some of the others who did the initial work on the Pi work or worked for...Broadcom. Broadcom was generous enough to allow the RPF to buy modest lots of BCM2835 chips at a price normally reserved for much higher volumes. Of course, after the first few months, the volumes of chip purchases were at a level that the price was "normal". By using the BCM2835, those doing the early software work got a leg up be being already familiar with various parts of the chip architecture. So...a win-win. Broadcom gets really good PR (hasn't the Pi made you think kindly about Broadcom?) and the RPF got a good deal to help get the project successfully off the ground.

Exactly. My impression of Broadcom has tremendously improved with Rpi. I have dealt with Broadcom people in the past and they come across as stuck-up to people working in small-and-medium companies. Rpi has improved that impression somewhat.

I guess Intel chips weren't cost-competitive then. I don't think power consumption is a big issue since Rpi is not meant to be battery-operated.

[W. H. Heydt]

I guess Intel chips weren't cost-competitive then. I don't think power consumption is a big issue since Rpi is not meant to be battery-operated.

Not so much "weren't" as "aren't". They're still too expensive for inexpensive SBCs. Look at the prices of Intel SBCs. Lowest cost one I can think of is $90. Now some that is going to be profit (Intel is famous--infamous?--for high profit margins), but not all of it. While many Pis are powered from the wall, not all by any means. There are robotics and remote sensing applications in which Pis are used. Some people ask about shutting down subsystems to conserve power. Sometimes, power saving on the order of 10s of milliwatts matters. so starting with an SoC that draws 3, 4, 5 times the power isn't going start out very favorable.

[fruitoftheloom]

BCM2836 chosen as the CPU for RPi?

The BCM2835/36 are not a CPU it is a SoC

It has two parts the GPU & CPU

All RPi have VideoCore GPU which has a ARM CPU attached see: https://en.wikipedia.org/wiki/Raspberry_Pi

The VideoCore GPU was developed in the late 90's for STB's and therefore by the time EU worked for Broadcom the cost of R&D had been recouped.

An ARM llicence to manufacture a CPU is considerably cheaper then Intel, AMD & VIA because of the Business Model ARM Holdings use:

http://techreport.com/review/25067/an-i ... things-arm

The original BC2835 was end of life and apart from the ROKU it was not commercially used, therefore to Broadcom an end of life SoC could be sold at a very advantageous price. With the RPi 2B the ARMv6 CPU was swapped for an ARMv7 CPU which was a cost incurred by the RPF and its manufacturing partners but considering that 4K RPi's had been sold it was the most cost effective solution to ensure backward compatibilty.

[rpdom]

but considering that 4K 4,000,000 RPi's had been sold

FTFY

[fruitoftheloom]

but considering that 4K 4,000,000 RPi's had been sold

FTFY

WHATEVER !!! Yes it should be 5 Million+ for pre 2B https://www.raspberrypi.org/blog/five-million-sold

[rpdom]

WHATEVER !!! Yes it should be 5 Million+ for pre 2B https://www.raspberrypi.org/blog/five-million-sold

No worries.
It's early. Everyone makes mistakes (yes, even me)

[fruitoftheloom]

WHATEVER !!! Yes it should be 5 Million+ for pre 2B https://www.raspberrypi.org/blog/five-million-sold

No worries.
It's early. Everyone makes mistakes (yes, even me)

Ye Gods https://www.youtube.com/watch?v=mLNrLI3OBwg

[jamesh]

BCM2836 chosen as the CPU for RPi?

The BCM2835/36 are not a CPU it is a SoC

It has two parts the GPU & CPU

All RPi have VideoCore GPU which has a ARM CPU attached see: https://en.wikipedia.org/wiki/Raspberry_Pi

The VideoCore GPU was developed in the late 90's for STB's and therefore by the time EU worked for Broadcom the cost of R&D had been recouped.

An ARM llicence to manufacture a CPU is considerably cheaper then Intel, AMD & VIA because of the Business Model ARM Holdings use:

http://techreport.com/review/25067/an-i ... things-arm

The original BC2835 was end of life and apart from the ROKU it was not commercially used, therefore to Broadcom an end of life SoC could be sold at a very advantageous price. With the RPi 2B the ARMv6 CPU was swapped for an ARMv7 CPU which was a cost incurred by the RPF and its manufacturing partners but considering that 4K RPi's had been sold it was the most cost effective solution to ensure backward compatibilty.

A chip called the 2763, which is almost identical to the 2835, was used in the last of the Symbian Nokia phones, including the 808. In addition, the Videocore4 was used in a number of Samsung phones. So to say only Roku isn't quite true (I think Amazon may even have used the 2835 at some point).